Evolution of dynamic recrystallisation in AISI 304 stainless steel

Abstract

The nucleation and development of dynamic recrystallisation (DRX) has been studied via hot torsion testing of AISI 304 stainless steel. The DRX behaviour was investigated with microstructural analysis and slope changes of ow stress curves. The characteristics of serrated grain boundaries observed by SEM, electron backscattered diffraction and TEM indicated that the nucleated DRX grain size was similar to that of the bulged part of the original grain boundary. The DRX of the alloy was nucleated and developed by strain induced grain boundary migration and by the necklace mechanism. Before the steady state in the ow curve at 1000°C and 0 . 5 s 1 , the dynamically recrystallised grains did not remain a constant size and gradually grew to the size of fully DRX grains at steady state (30 mm). The calculation of the grain size was based on X DRX (volume fraction of dynamically recrystallisation) under the assumption that the nucleated DRX grains grow to the steady state continuously. It was found that the calculated grain size of the alloy was good agreement with that of the observed grain size. It is expected that a ne grained steel can be obtained by controlling hot deformation conditions on the basis of newly developed equations for predicting DRX behaviour. MST/5437The authors are in the

A new topological approach for the mean field modeling of dynamic recrystallization

“…In the present approach, necklace nucleation is considered since this is the kind of nucleation observed in 304L during DRX [26,27]. Thereafter, the quantities θ (i) and 145 …”

Simulation of Continuous Dynamic Recrystallization Using a Level-Set Method

“…Until now, most of the research efforts at the mesoscopic scale have been applied to observe, characterize, and model DDRX. This appears natural, because common study materials such as stainless steels and nickel-based superalloys undergo these mechanisms under a usual range of thermomechanical parameters [ 5 , 6 ]. In addition, it should be mentioned that modeling DDRX at the mesoscale is more evident because nucleation of recrystallized grains can be implemented naturally within common simulation frameworks [ 7 ], whereas modeling CDRX requires the ability to describe substructure formation and evolution.…”